Surgical balloons have a variety of uses, including the containment of fluids used to necrose cells lining a body cavity. For example, it has now become common to treat excessive menstrual bleeding (menorrhagia) by inserting a balloon catheter into the uterus, filling the balloon with a thermally conductive media and heating or cooling the media to thermally kill the endometrial lining of the uterus. An exemplary thermal ablation process and apparatus utilizing a surgical balloon are described in U.S. Pat. No. 5,501,681 to Neuwirth et al.
As shown in U.S. Pat. No. 5,501,681, known surgical balloons are typically formed from latex, have a bulb shape, and inflate in a manner which enlarges the bulb shape uniformly to an approximately spherical or bulbous shape. In contrast, the uterine cavity is Y-shaped in cross-section. The material composition of known balloons is somewhat inelastic, preventing the balloons from readily conforming to the intra-uterine space. As a result, known bulbous surgical balloons do not inflate to contact the entire endometrial lining, in particular, in the area of the uterine cornua. This lack of contact may result in a portion of the endometrial lining escaping treatment.
It is therefore an object of the present invention to provide an improved surgical balloon that exhibits an increased contact area with a body cavity into which it is inserted when the balloon is inflated.